Methods and devices for soft palate tissue elevation procedures

ABSTRACT

A self-retaining suture having particular application for treating obstructive sleep apnea and use thereof. The suture includes rising an elongated suture body having a periphery and first and second tissue-penetrating ends each with a bi-curve needle, and a plurality of first retainers on a first segment and oriented to the first end, and a plurality of second retainers a second segment and oriented to the second end, and a retainer-free transition segment disposed between the pluralities of first and second retainers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application claiming priority to U.S.patent application Ser. No. 13/488,527, filed on Jun. 5, 2012, whichclaims the benefit of U.S. Provisional Appln. Ser. No. 61/493,941 filedon Jun. 6, 2011.

FIELD OF THE INVENTION

The present invention relates generally to self-retaining sutures andmethods for using self-retaining sutures in soft palate elevationprocedures.

BACKGROUND OF THE INVENTION

Wound closure devices such as sutures, staples and tacks have beenwidely used in superficial and deep surgical procedures in humans andanimals for closing wounds, repairing traumatic injuries or defects,joining tissues together (bringing severed tissues into approximation,closing an anatomical space, affixing single or multiple tissue layerstogether, creating an anastomosis between two hollow/luminal structures,adjoining tissues, attaching or reattaching tissues to their properanatomical location), attaching foreign elements to tissues (affixingmedical implants, devices, prostheses and other functional or supportivedevices), and for repositioning tissues to new anatomical locations(repairs, tissue elevations, tissue grafting and related procedures) toname but a few examples.

Sutures are often used as wound closure devices. Sutures typicallyconsist of a filamentous suture thread attached to a needle with a sharppoint. Suture threads can be made from a wide variety of materialsincluding bioabsorbable (i.e., that break down completely in the bodyover time), or non-absorbable (permanent; non-degradable) materials.Absorbable sutures have been found to be particularly useful insituations where suture removal might jeopardize the repair or where thenatural healing process renders the support provided by the suturematerial unnecessary after wound healing has been completed; as in, forexample, completing an uncomplicated skin closure. Non-degradable(non-absorbable) sutures are used in wounds where healing may beexpected to be protracted or where the suture material is needed toprovide physical support to the wound for long periods of time; as in,for example, deep tissue repairs, high tension wounds, many orthopedicrepairs and some types of surgical anastomosis. Also, a wide variety ofsurgical needles are available; the shape and size of the needle bodyand the configuration of the needle tip is typically selected based uponthe needs of the particular application.

To use an ordinary suture, a suture needle is advanced through thedesired tissue on one side of the wound and then through the adjacentside of the wound. The suture is then formed into a “loop” which iscompleted by tying a knot in the suture to hold the wound closed. Knottying takes time and causes a range of complications, including, but notlimited to (i) spitting, a condition where the suture, usually a knot,pushes through the skin after a subcutaneous closure), (ii) infection(bacteria are often able to attach and grow in the spaces created by aknot), (iii) bulk/mass (a significant amount of suture material left ina wound is the portion that comprises the knot), (iv) slippage (knotscan slip or come untied), and (v) irritation (knots serve as a bulk“foreign body” in a wound). Suture loops associated with knot tying maylead to ischemia (knots can create tension points that can strangulatetissue and limit blood flow to the region) and increased risk ofdehiscence or rupture at the surgical wound. Knot tying is also laborintensive and can comprise a significant percentage of the time spentclosing a surgical wound. Additional operative procedure time is notonly bad for the patient (complication rates rise with time spent underanesthesia), but it also adds to the overall cost of the operation (manysurgical procedures are estimated to cost between $15 and $30 per minuteof operating time).

Self-retaining sutures (including barbed sutures) differ fromconventional sutures in that self-retaining sutures possess numeroustissue retainers (such as barbs) which anchor the self-retaining sutureinto the tissue following deployment and resist movement of the suturein a direction opposite to that in which the retainers face, therebyeliminating the need to tie knots to affix adjacent tissues together (a“knotless” closure). Knotless tissue-approximating devices having barbshave been previously described in, for example, U.S. Pat. No. 5,374,268,disclosing armed anchors having barb-like projections, while sutureassemblies having barbed lateral members have been described in U.S.Pat. Nos. 5,584,859 and 6,264,675. Sutures having a plurality of barbspositioned along a greater portion of the suture are described in U.S.Pat. No. 5,931,855, which discloses a unidirectional barbed suture, andU.S. Pat. No. 6,241,747, which discloses a bidirectional barbed suture.Methods and apparatus for forming barbs on sutures have been describedin, for example, U.S. Pat. No. 6,848,152. Self-retaining systems forwound closure also result in better approximation of the wound edges,evenly distribute the tension along the length of the wound (reducingareas of tension that can break or lead to ischemia), decrease the bulkof suture material remaining in the wound (by eliminating knots) andreduce spitting (the extrusion of suture material-typicallyknots—through the surface of the skin). Various patterns and densitiesof retainer dispositions on sutures, and methods for making same, havebeen described, for example, in PCT/US2011/034660. All of these featuresare thought to reduce scarring, improve cosmesis, and increase woundstrength relative to wound closures using plain sutures or staples.Thus, self-retaining sutures, because such sutures avoid knot tying,allow patients to experience an improved clinical outcome, and also savetime and costs associated with extended surgeries and follow-uptreatments. It is noted that all patents, patent applications and patentpublications identified throughout are incorporated herein by referencein their entirety.

The ability of self-retaining sutures to anchor and hold tissues inplace even in the absence of tension applied to the suture by a knot isa feature that also provides superiority over plain sutures. Whenclosing a wound that is under tension, this advantage manifests itselfin several ways: (i) self-retaining sutures have a multiplicity ofretainers which can dissipate tension along the entire length of thesuture (providing hundreds of “anchor” points that produce a superiorcosmetic result and lessens the chance that the suture will “slip” orpull through) as opposed to knotted interrupted sutures whichconcentrate the tension at discrete points; (ii) complicated woundgeometries can be closed (circles, arcs, jagged edges) in a uniformmanner with more precision and accuracy than can be achieved withinterrupted sutures; (iii) self-retaining sutures eliminate the need fora “third hand” which is often required for maintaining tension acrossthe wound during traditional suturing and knot tying (to prevent“slippage” when tension is momentarily released during tying); (iv)self-retaining sutures are superior in procedures where knot tying istechnically difficult, such as in deep wounds or laparoscopic/endoscopicprocedures; and (v) self-retaining sutures can be used to approximateand hold the wound prior to definitive closure. As a result,self-retaining sutures provide easier handling in anatomically tight ordeep places (such as the pelvis, abdomen and thorax) and make it easierto approximate tissues in laparoscopic/endoscopic and minimally invasiveprocedures; all without having to secure the closure via a knot. Greateraccuracy allows self-retaining sutures to be used for more complexclosures (such as those with diameter mismatches, larger defects orpurse string suturing) than can be accomplished with plain sutures.

A self-retaining suture may be unidirectional, having one or moreretainers oriented in one direction along the length of the suturethread; or bidirectional, typically having one or more retainersoriented in one direction along a portion of the thread, followed by oneor more retainers oriented in another (often opposite) direction over adifferent portion of the thread (as described with barbed retainers inU.S. Pat. Nos. 5,931,855 and 6,241,747). Although any number ofsequential or intermittent configurations of retainers are possible, acommon form of bidirectional self-retaining suture involves a needle atone end of a suture thread which has barbs having tips projecting “away”from the needle until the transition point (often the midpoint) of thesuture is reached; at the transition point the configuration of barbsreverses itself about 180° (such that the barbs are now facing in theopposite direction) along the remaining length of the suture threadbefore attaching to a second needle at the opposite end (with the resultthat the barbs on this portion of the suture also have tips projecting“away” from the nearest needle). Projecting “away” from the needle meansthat the tip of the barb is further away from the needle and the portionof suture comprising the barb may be pulled more easily through tissuein the direction of the needle than in the opposite direction. Putanother way, the barbs on both “halves” of a typical bidirectionalself-retaining suture have tips that point towards the middle, with atransition segment (lacking barbs) interspersed between them, and with aneedle attached to either end.

Various devices and treatments have been developed for soft palatetissues to alleviate conditions such as sleep apnea and snoring, whichcan be caused by the relaxation and collapse of the soft palate into theairway. These include wearing of devices such as face masks providingcontinuous positive airway pressure and mandibular advancement devices;however, such treatments necessarily rely on ongoing patient complianceto be effective. More permanent treatments include surgical uvuloplastyand laser-assisted uvuloplasty, in which the volume of the uvula isirreversibly reduced by removal of uvular tissue. Reduction of uvulavolume can result in adverse effects such as occlusion of the airway bythe base of the tongue and restriction of the velopharynx and oropharynxdue to postoperative scarring, both of which can contribute to anincrease in sleep apnea. Other surgical treatments involve stiffeningthe soft palate to prevent the collapse of the soft palate into theairway by the introduction of implants or sclerosants into the softpalate. The former include the PILLAR™ Palatal Implant System (RestoreMedical Inc., St. Paul, Minn.), and can have adverse effects such asextrusion of the implant and associated effects (including infection,further surgical procedures for removal of the implant, etc.).Introduction of sclerosants include procedures such as injectionsnoreplasty, in which the injection of a sclerosant is intended toresult in scarring of the soft palate. These procedures can result inongoing patient discomfort (including sore throat, a perception ofsomething being stuck in the throat), and in any event are notrecommended for patients having obstructive sleep apnea.

To avoid these effects, procedures focussing on the height of the softpalate have also been developed. For example, in a procedure known asSNORELIFT™ developed by Dr. Bülent Ugurlu of the Hamburg MilitaryHospital, two unidirectional self-retaining sutures are deployed intothe soft palate from opposing sides of the palate midline in asubstantially mirror-image configuration. In this procedure, the firstunidirectional suture is inserted into the soft palate on one side ofthe palate midline and is pushed posteriorly through the palate and outat a first exit point. The first suture is then reinserted into the softpalate at a second insertion point posterior to the first exit point,potentially leaving a segment of the self-retaining suture in the oralcavity, and then pushed through the soft palate tissue diagonally acrossthe midline to a second exit point. The process is repeated with asecond unidirectional suture inserted into the soft palate at the otherside of the midline, creating a criss-cross pattern. Drawing each sutureout of its second exit point and tensioning the suture results in theelevation of the soft palate, particularly in the region where thesuture is exposed in the oral cavity. As this procedure is performedwith two unidirectional sutures, there is some risk of suture extrusionunless the trailing ends of each suture are somehow anchored (by, forexample, knot-tying), and such anchoring can itself provide a nidus forinfection, etc, while any exposed suture remaining in the oral cavitycan create issues with healing and infection. Moreover, the procedurecan cause bunching of soft palate tissue.

SUMMARY OF THE INVENTION

It is desirable to provide bidirectional self-retaining sutures havingconfigurations particularly suited to soft palate elevation procedures.Thus, it is desirable to provide improved self-retaining sutures havingenhanced clinical performance in soft palate elevation.

It is also desirable to provide improved surgical methods of alleviatingconditions of snoring and sleep apnea. Thus, it is desirable to providesurgical methods providing improved clinical outcomes in soft palateelevation procedures.

In one embodiment, the present invention provides a method ofapproximating soft palate tissue using a bidirectional self-retainingsuture having first and second tissue-penetrating ends, first and secondpluralities of tissue retainers oriented towards the first and secondends, respectively, and separated by a retainer-free transition segment.The method includes inserting the first end of a suture into the softpalate at an insertion point to one side of the palate midline andbetween the junction of the hard and soft palates and the posterior endof the soft palate, deploying the first end through the soft palateacross the palate midline to a first exit point to the other side of thepalate midline and between the junction of the hard and soft palates andthe posterior end of the soft palate, urging the first end out of thesoft palate at the first exit point and drawing the suture through thesoft palate until the second plurality of tissue retainers engage thetissue, re-inserting the first end into the first exit point anddeploying the first end through the soft palate posteriorly and awayfrom the palate midline to a second exit point, urging the first end outof the soft palate at the second exit point and drawing the suture outthrough the second exit point, inserting the second end into theinsertion point and deploying the second end through the soft palateposteriorly and away from the palate midline to a third exit point, andurging the second end out of the soft palate at the third exit point anddrawing the suture out through the third exit point.

The method may further include trimming the suture flush with the secondand third exit points.

In yet another embodiment, the method further includes drawing thesuture anteriorly and cranially in the last urging step to increaseelevation of the soft palate.

The drawing of the suture may result in a volumetric increase in theairway of a patient.

In yet another embodiment, the first and second tissue penetrating endsof the suture further include first and second bi-curve needles attachedto first and second ends of the suture respectively. The bi-curveneedles may have a length of approximately 28-32 mm.

Also provided is a surgical kit for soft palate elevation procedureshaving a suture assembly including an elongated suture body having aperiphery and first and second tissue-penetrating ends, each of whichare provided with a needle having a curvature, a plurality of firstretainers disposed on a first segment of the elongated body and orientedto the first end, the first plurality of retainers yielding toward thesuture body during movement of the suture through tissue in a directionof deployment of the first end, and resisting movement of the suture,when in tissue, in a direction substantially opposite to the directionof deployment of the first end, a plurality of second retainers disposedon a second segment of the elongated body and oriented to the secondend, the plurality of second retainers yielding toward the suture bodyduring movement of the suture through tissue in a direction ofdeployment of the second end, and resisting movement, when in tissue, ina direction substantially opposite the direction of deployment of thesecond end, and a retainer-free transition segment disposed between thepluralities of first and second retainers, the transition segment havinga length of up to 10 mm. The kit further includes a needle driver,forceps, scissors, and a tongue depressor.

The suture assembly may be made of a bio-absorbable material, or anon-absorbable material.

According to one embodiment, the length of the transition segment isbetween 0.5 and 5 mm.

According to yet another embodiment, the first and second segments havea length less than 70 mm.

In yet another embodiment, the first and second retainers are arrangedin a helical pattern, which may optionally be a double helix or aquadra-helix. The retainer density of the helical pattern may further beat least 250 per centimeter.

The present invention also provides a self-retaining suture including anelongated suture body having a periphery and first and secondtissue-penetrating ends, each of the first and second ends beingprovided with a bi-curve needle, a plurality of first retainers disposedon a first segment of the elongated body and oriented to the first end,the first plurality of retainers yielding toward the suture body duringmovement of the suture through tissue in a direction of deployment ofthe first end, and resisting movement of the suture, when in tissue, ina direction substantially opposite to the direction of deployment of thefirst end, a plurality of second retainers disposed on a second segmentof the elongated body and oriented to the second end, the plurality ofsecond retainers yielding toward the suture body during movement of thesuture through tissue in a direction of deployment of the second end,and resisting movement, when in tissue, in a direction substantiallyopposite the direction of deployment of the second end, and aretainer-free transition segment disposed between the pluralities offirst and second retainers.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the invention, and the nature and various advantages thereofwill be apparent from the accompanying drawings and the followingdetailed description of various embodiments of the invention.

FIGS. 1A and 1B are views of a self-retaining suture in accordance withan embodiment of the present invention.

FIG. 2A is a perspective view of a self-retaining suture havingretainers distributed in a single helix pattern according to anembodiment of the invention.

FIG. 2B is a perspective view of a self-retaining suture havingretainers distributed in a double helix pattern according to anembodiment of the invention.

FIG. 2C is a perspective view of a self-retaining suture havingretainers distributed in a quadra-helix pattern according to anembodiment of the invention.

FIGS. 3A and 3B are views of a method of soft palate elevation inaccordance with an embodiment of the invention.

FIG. 4 is a view of a surgical kit for use in soft palate elevationprocedures in accordance with an embodiment of the present invention.

FIGS. 5A and 5B illustrate an exemplary bi-curve needle according to anembodiment of the invention.

DETAILED DESCRIPTION

Definitions

Definitions of certain terms that may be used hereinafter include thefollowing.

“Self-retaining suture” refers to a surgical suture that includesfeatures on the suture thread for engaging tissue without the need for aknot or suture anchor. A “self-retaining suture” may also includedevices for deploying the suture into tissue. Such deployment devicesinclude, without limitation, suture needles and other deployment devicesas well as sufficiently rigid and sharp ends on the suture itself topenetrate tissue.

“Tissue retainer” (or simply “retainer”) refers to a physical feature ofa suture thread which is adapted to mechanically engage tissue andresist movement of the suture in at least one axial direction. By way ofexample only, tissue retainer or retainers can include hooks,projections, barbs, darts, extensions, bulges, anchors, protuberances,spurs, bumps, points, cogs, tissue engagers, traction devices, surfaceroughness, surface irregularities, surface defects, edges, facets andthe like. In certain configurations, tissue retainers are adapted toengage tissue to resist movement of the suture in a direction other thanthe direction in which the suture is deployed into the tissue by thesurgeon, by being oriented to substantially face the deploymentdirection. In some embodiments the retainers lie flat when pulled in thedeployment direction and open or “fan out” when pulled in a directioncontrary to the deployment direction. As the tissue-penetrating end ofeach retainer faces away from the deployment direction when movingthrough tissue during deployment, the tissue retainers should not catchor grab tissue during this phase. Once the self-retaining suture hasbeen deployed, a force exerted in another direction (often substantiallyopposite to the deployment direction) causes the retainers to bedisplaced from the deployment position (i.e. resting substantially alongthe suture body), forces the retainer ends to open (or “fan out”) fromthe suture body in a manner that catches and penetrates into thesurrounding tissue, and results in tissue being caught between theretainer and the suture body; thereby “anchoring” or affixing theself-retaining suture in place. In certain other embodiments, the tissueretainers may be configured to permit motion of the suture in onedirection and resist movement of the suture in another direction withoutfanning out or deploying. In each of the sutures and retainers of thepresent invention, in one optional embodiment, the retainers may becharacterized as a plurality of barbs extending from the periphery ofthe body and tapering from a broad base to a narrow tip. In addition, oralso optionally, the retainers may be characterized as a plurality ofbarbs that yield toward the suture body during movement of the suturethrough the tissue in the desired direction of movement of the suturethrough the tissue, and the barbs resist movement of the suture throughthe tissue in a direction opposite the desired direction of movement ofthe suture. Typically, a needle will be located at an end of the suture,and the barbs will yield toward the suture body as the suture is pulledthrough tissue in the direction that the needle is moving. In certainother configurations, the tissue retainer may be configured or combinedwith other tissue retainers to resist motion of the suture in eitherdirection. Typically, a suture having such retainers is deployed througha device such as a cannula which prevents contact between the retainersand the tissue until the suture is in the desired location.

“Retainer configurations” refers to configurations of tissue retainersand can include features such as size, shape, flexibility, surfacecharacteristics, and so forth. These are sometimes also referred to as“barb configurations”.

“Retainer distribution” and “retainer pattern” refers to the arrangementof retainers along and around a suture thread and can include featuressuch as density and orientation.

“Bidirectional suture” refers to a self-retaining suture havingretainers oriented in one direction at one end and retainers oriented inthe other direction at the other end. A bidirectional suture istypically armed with a needle at each end of the suture thread. Abidirectional suture may have a transition segment.

“Transition segment” refers to a retainer-free (barb-free) portion of abidirectional suture located between a first set of retainers (barbs)oriented in one direction and a second set of retainers (barbs) orientedin another direction. The transition segment can be at about themidpoint of the self-retaining suture, or closer to one end of theself-retaining suture to form an asymmetrical self-retaining suture.

“Suture thread” refers to the filamentary body component of a suture orsutures. The suture thread may be a monofilament, or contain multiplefilaments as in a braided suture. The suture thread may be made of anysuitable biocompatible material, and may be further treated with anysuitable biocompatible material, whether to enhance the sutures'strength, resilience, longevity, or other qualities, or to equip thesutures to fulfill additional functions besides joining tissuestogether, repositioning tissues, or attaching foreign elements totissues.

“Monofilament suture” refers to a suture comprising a monofilamentarysuture thread.

“Braided suture” refers to a suture comprising a multifilamentary suturethread. The filaments in such suture threads are typically braided,twisted, or woven together.

“Degradable suture” (also referred to as “biodegradable suture” or“absorbable suture” or “bio-absorbable suture”) refers to a suturewhich, after introduction into a tissue is broken down and absorbed bythe body. Typically, the degradation process is at least partiallymediated by, or performed in, a biological system. “Degradation” refersto a chain scission process by which a polymer chain is cleaved intooligomers and monomers. Chain scission may occur through variousmechanisms, including, for example, by chemical reaction (e.g.,hydrolysis, oxidation/reduction, enzymatic mechanisms or a combinationof these) or by a thermal or photolytic process. Degradable suturematerial may include polymers such as polyglycolic acid, copolymers ofglycolide and lactide, copolymers of trimethylene carbonate andglycolide with diethylene glycol (e.g., MAXON™, Tyco Healthcare Group),terpolymer composed of glycolide, trimethylene carbonate, and dioxanone(e.g., BIOSYN™ [glycolide (60%), trimethylene carbonate (26%), anddioxanone (14%)], Tyco Healthcare Group), copolymers of glycolide,caprolactone, trimethylene carbonate, and lactide (e.g., CAPROSYN™, TycoHealthcare Group). A dissolvable suture can also include partiallydeacetylated polyvinyl alcohol. Polymers suitable for use in degradablesutures can be linear polymers, branched polymers or multi-axialpolymers. Examples of multiaxial polymers used in sutures are describedin U.S. Patent Application Publication Nos. 2002/0161168, 2004/0024169,and 2004/0116620. Sutures made from degradable suture material losetensile strength as the material degrades. Degradable sutures can be ineither a braided multifilament form or a monofilament form.

“Non-degradable suture” (also referred to as “non-absorbable suture”)refers to a suture comprising material that is not degraded by chainscission such as chemical reaction processes (e.g., hydrolysis,oxidation/reduction, enzymatic mechanisms or a combination of these) orby a thermal or photolytic process. Non-degradable suture materialincludes polyamide (also known as nylon, such as nylon 6 and nylon 6.6),polyester (e.g., polyethylene terephthlate), polytetrafluoroethylene(e.g., expanded polytetrafluoroethylene), polyether-ester such aspolybutester (block copolymer of butylene terephthalate and polytetramethylene ether glycol), polyurethane, metal alloys, metal (e.g.,stainless steel wire), polypropylene, polyethelene, silk, and cotton.Sutures made of non-degradable suture material are suitable forapplications in which the suture is meant to remain permanently or ismeant to be physically removed from the body.

“Suture diameter” refers to the diameter of the body of the suture. Itis to be understood that a variety of suture lengths may be used withthe sutures described herein and that while the term “diameter” is oftenassociated with a circular periphery, it is to be understood herein toindicate a cross-sectional dimension associated with a periphery of anyshape. Suture sizing is based upon diameter. United States Pharmacopeia(“USP”) designation of suture size runs from 0 to 7 in the larger rangeand 1-0 to 11-0 in the smaller range; in the smaller range, the higherthe value preceding the hyphenated zero, the smaller the suturediameter. The actual diameter of a suture will depend on the suturematerial, so that, by way of example, a suture of size 5-0 and made ofcollagen will have a diameter of 0.15 mm, while sutures having the sameUSP size designation but made of a synthetic absorbable material or anon-absorbable material will each have a diameter of 0.1 mm. Theselection of suture size for a particular purpose depends upon factorssuch as the nature of the tissue to be sutured and the importance ofcosmetic concerns; while smaller sutures may be more easily manipulatedthrough tight surgical sites and are associated with less scarring, thetensile strength of a suture manufactured from a given material tends todecrease with decreasing size. It is to be understood that the suturesand methods of manufacturing sutures disclosed herein are suited to avariety of diameters, including without limitation 7, 6, 5, 4, 3, 2, 1,0, 1-0, 2-0, 3-0, 4-0, 5-0, 6-0, 7-0, 8-0, 9-0, 10-0, 11-0 and 12-0.

“Suture deployment end” refers to an end of the suture to be deployedinto tissue; one or both ends of the suture may be suture deploymentends. The suture deployment end may be attached to a deployment devicesuch as a suture needle, or may be sufficiently sharp and rigid topenetrate tissue on its own.

“Needle attachment” refers to the attachment of a needle to a suturerequiring same for deployment into tissue, and can include methods suchas crimping, swaging, using adhesives, and so forth. The suture threadis attached to the suture needle using methods such as crimping, swagingand adhesives. Attachment of sutures and surgical needles is describedin U.S. Pat. Nos. 3,981,307, 5,084,063, 5,102,418, 5,123,911, 5,500,991,5,722,991, 6,012,216, and 6,163,948, and U.S. Patent ApplicationPublication No. US 2004/0088003) all of which are incorporated herein byreference. The point of attachment of the suture to the needle is knownas the swage. “Armed suture” refers to a suture having a suture needleon at least one suture deployment end.

“Suture needle” refers to needles used to deploy sutures into tissue,which come in many different shapes, forms and compositions. There aretwo main types of needles, traumatic needles and atraumatic needles.Traumatic needles have channels or drilled ends (that is, holes or eyes)and are supplied separate from the suture thread and are threaded onsite. Atraumatic needles are eyeless and are attached to the suture atthe factory by swaging or other methods whereby the suture material isinserted into a channel at the blunt end of the needle which is thendeformed to a final shape to hold the suture and needle together. Assuch, atraumatic needles do not require extra time on site for threadingand the suture end at the needle attachment site is generally smallerthan the needle body. In the traumatic needle the thread comes out ofthe needle's hole on both sides and often the suture rips the tissues toa certain extent as it passes through. Most modern sutures are swagedatraumatic needles. Atraumatic needles may be permanently swaged to thesuture or may be designed to come off the suture with a sharp straighttug. These “pop-offs” are commonly used for interrupted sutures, whereeach suture is only passed once and then tied. For barbed sutures thatare uninterrupted, these atraumatic needles are preferred.

Suture needles may also be classified according to the geometry of thetip or point of the needle. For example, needles may be (i) “tapered”whereby the needle body is round and tapers smoothly to a point; (ii)“cutting” whereby the needle body is triangular and has sharpenedcutting edge on the inside; (iii) “reverse cutting” whereby the cuttingedge is on the outside; (iv) “trocar point” or “taper cut” whereby theneedle body is round and tapered, but ends in a small triangular cuttingpoint; (v) “blunt” points for sewing friable tissues; (vi) “sidecutting” or “spatula points” whereby the needle is flat on top andbottom with a cutting edge along the front to one side (these aretypically used for eye surgery).

Suture needles may also be of several shapes including, (i) straight,(ii) half curved or ski, (iii) ¼ circle, (iv) ⅜ circle, (v) ½ circle,(vi) ⅝ circle, (v) bi-curve, and (vi) compound curve. The suturesdescribed herein may be deployed with a variety of needle types(including without limitation curved, straight, long, short, micro, andso forth), needle cutting surfaces (including without limitation,cutting, tapered, and so forth), and needle attachment techniques(including without limitation, drilled end, crimped, and so forth).Moreover, the sutures described herein may themselves includesufficiently rigid and sharp ends so as to dispense with the requirementfor deployment needles altogether. Suturing needles are described, forexample, in U.S. Pat. Nos. 6,322,581; 6,214,030; 5,464,422; 5,941,899;5,425,746; 5,306,288; 5,156,615; 5,312,422; 7,063,716; 6,129,741;5,897,572; 5,676,675; and 5,693,072 all of which are incorporated hereinby reference.

“Needle diameter” refers to the diameter of a suture deployment needleat the widest point of that needle. While the term “diameter” is oftenassociated with a circular periphery, it is to be understood herein toindicate a cross-sectional dimension associated with a periphery of anyshape. In preferred embodiments of self-retaining suture, the needlediameter is less than the maximum diameter/cross-sectional dimension ofthe retainers on the suture.

“Tissue elevation procedure” refers to a surgical procedure forrepositioning tissue from a lower elevation to a higher elevation (i.e.moving the tissue in a direction opposite to the direction of gravity).The retaining ligaments of the face support facial soft tissue in thenormal anatomic position. However, with age, gravitational effects andloss of tissue volume effect downward migration of tissue, and fatdescends into the plane between the superficial and deep facial fascia,thus allowing facial tissue to sag. Face-lift procedures are designed tolift these sagging tissues, and are one example of a more general classof medical procedure known as a tissue elevation procedure. Moregenerally, a tissue elevation procedure reverses the appearance changethat results from effects of aging and gravity over time, and othertemporal effects that cause tissue to sag, such as genetic effects. Itshould be noted that tissue can also be repositioned without elevation;in some procedures tissues are repositioned laterally (away from themidline), medially (towards the midline) or inferiorly (lowered) inorder to restore symmetry (i.e., repositioned such that the left andright sides of the body “match”).

“Medical device” or “implant” refers to any object placed in the bodyfor the purpose of restoring physiological function,reducing/alleviating symptoms associated with disease, and/or repairingand/or replacing damaged or diseased organs and tissues. While normallycomposed of biologically compatible synthetic materials (e.g.,medical-grade stainless steel, titanium and other metals or polymerssuch as polyurethane, silicon, PLA, PLGA and other materials) that areexogenous, some medical devices and implants include materials derivedfrom animals (e.g., “xenografts” such as whole animal organs; animaltissues such as heart valves; naturally occurring or chemically-modifiedmolecules such as collagen, hyaluronic acid, proteins, carbohydrates andothers), human donors (e.g., “allografts” such as whole organs; tissuessuch as bone grafts, skin grafts and others), or from the patientsthemselves (e.g., “autografts” such as saphenous vein grafts, skingrafts, tendon/ligament/muscle transplants). Medical devices that can beused in procedures in conjunction with the present invention include,but are not restricted to, orthopedic implants (artificial joints,ligaments and tendons; screws, plates, and other implantable hardware),dental implants, intravascular implants (arterial and venous vascularbypass grafts, hemodialysis access grafts; both autologous andsynthetic), skin grafts (autologous, synthetic), tubes, drains,implantable tissue bulking agents, pumps, shunts, sealants, surgicalmeshes (e.g., hernia repair meshes, tissue scaffolds), fistulatreatments, spinal implants (e.g., artificial intervertebral discs,spinal fusion devices, etc.) and the like.

Self-Retaining Sutures

As discussed above, the present invention provides self-retainingsutures and methods of using self-retaining sutures in soft palateelevation surgical procedures.

FIG. 1A illustrates an embodiment of a bidirectional self-retainingsuture 100. Self-retaining suture 100 includes needles 110, 112 attachedto suture thread 120. Self-retaining suture 100 includes a plurality ofretainers 130 distributed on the surface of a suture thread 120. Theretainers 130 are elevated as shown in FIG. 1A. In lead-in region 140 ofsuture thread 120 there are no retainers 130. In region 142 of suturethread 120 there are a plurality of retainers 130 arranged such that thesuture can be moved through tissue in the direction of needle 110 butresists movement in the direction of needle 112. In transition region144, there are no retainers 130. In region 146, there is a plurality ofretainers 130 arranged such that the suture can be moved through tissuein the direction of needle 112 but resists movement in the direction ofneedle 110. In lead-in region 148 of suture thread 120 there are noretainers 130. A break is shown in each of regions 140, 142, 144, 146and 148 to indicate that the length of each region may be varied andselected depending upon different variables, such as the gauge of thesuture being used or the surgeon's preference. For example, thetransition segment 144 may have a length in the range of about 0.5 mm toabout 5 mm, or in the range of about 0.5 mm to about 1.5 mm, or it maybe about 1 mm. Similarly, by way of example, one or both of regions 142and 146 may have a length of up to about 50 mm or up to about 70 mm; itis not necessary for these regions to have identical lengths.

Likewise the suture gauge and the configuration of each of needles 110and 112 can be any of the range of different surgical needles suitableto the present purpose. For instance, sutures of the present inventionmay suitably be provided in sizes 2-0, 3-0, 4-0, and 5-0, depending onthe material of the suture and retainer density, distribution, andconfiguration. Needles 110 and 112 may have the same configuration ordifferent configurations, such as bi-curve or compound curve. Thedimensions of the needles may also vary; they may be in the range ofabout 30 mm to 40 mm, or one or both may be about 32 mm.

FIG. IB illustrates a magnified view of self-retaining suture 100 inregion 142. As shown in FIG. IB, a plurality of retainers 130 isdistributed on the surface of suture thread 120. The affixation ofself-retaining sutures after deployment in tissue entails thepenetration of retainer tips 132 into the surrounding tissue resultingin tissue being caught between the retainer 130 and the body of suturethread 120. The inner retainer surface 134 of the retainer 130 that isin contact with the tissue that is caught between the retainer 130 andthe body of suture thread 120, is referred to herein as the “tissueengagement surface” or “inner retainer surface.” As illustrated in FIG.IB, each retainer 130 has a tip 132 and inner retainer surface 134. Whenself-retaining suture 100 is moved in the direction of arrow 156,retainers 130 in region 142 lie flat against the body of suture thread120. However, when self-retaining suture 100 is moved in the directionof arrow 158, tips 132 of retainers 130 in region 142 engage tissuesurrounding suture thread 120 and causes retainers 130 to fan out fromsuture thread 120 and engage the tissue with inner retainer surface 134thereby preventing movement of the suture in that direction. In region146, there is a plurality of retainers 130 arranged such that the suturecan be moved through tissue in the direction of arrow 158 but resistsmovement in the direction of arrow 156.

A self-retaining suture can, in some embodiments, include visible orvisualizable markings indicating, for example, the presence, absenceand/or orientation of retainers in a region of the suture. Thus, forexample, the bidirectional self-retaining suture 100 of FIG. 1A includesvisible markings 104 on the transition segment 144 which allow a surgeonto identify the location of transition segment 144. Many different kindsof markers may be suitable for marking the transition segment in thepresent invention, and can include, by way of example, different colorssuch as red, green, orange, yellow, green, blue etc. The markers can beformed by various conventional methods. For example, the markers can becoated, sprayed, glued, dyed, stained, or otherwise affixed to theself-retaining suture systems or components thereof. Traditionalcolourant application processes include, without limitation, dipping,spraying (by, for example, an ink jet), painting, printing, applyingand/or coating colourants on the suture section of interest. Criticalfluid extraction (such as carbon oxide) may also be used to addcolourant locally to all or part of the section desired to be marked.Alternatively, colourant(s) for the suture section of interest may beincluded in a portion of the suture material that is used to form thesuture body, wherein that portion is in the section of interest of themanufactured suture.

Additionally, the transition segment can be demarcated by using anenergy-activated colourant. For example, when a laser-activatedcolourant (that is, a pigment or dye which permanently changes colourafter being exposed to laser energy) is used to colour the suture, thenthe transition segment can be demarcated by using laser energy topermanently change the suture coating in the suture section of interest.This also applies to using other energy activated colourants which areactivated by other energy sources such as, but not limited to, heat,chemicals, microwaves, ultraviolet light, or x-rays. For example,bleaching chemicals such as sodium hypochlorite or hydrogen peroxidewill permanently change the colourant's colour which allows for thedemarcation of the eyelet or other region of the suture.

Additionally, the colourant(s) employed for demarcating the transitionsegment may be included on a plastic biocompatible material which isapplied on the suture at the section of interest. Such a layer may beabsorbable, such as a polyglycolide coating which has a colourant tomark transition segment, or it may be a non-absorbable material, such assilicone. The coloured material may be synthetic or may be derived froma natural source (whether the material be modified or unmodified), suchas collagen. The plastic biocompatible material may be applied to thesuture before or after the retainers are formed on the suture body.

Alternatively, the transition segment may be reverse-marked, such thatwhere the suture body is already visibly coloured, the colourant may beabsent from all or part of the suture section of interest such that atleast a portion of the section of interest is optically distinguishableby the surgeon from the rest of the suture. Such a suture may bemanufactured by including a colourant-free portion of suture material inthe suture section of interest area during the manufacture of the suturebody (for example, by extrusion) or by removal of colourant from thesuture section of interest after the suture body has been manufactured,whether before or after retainers have been formed on the suture body.Colourant may be removed locally by, for example, critical fluidextraction such as (e.g., carbon oxide). It is not necessary to removeall of the colourant from the section of interest of the suture as longas there is a difference detectible by a surgeon between the section ofinterest and the rest of the suture.

Another example of a reverse-marked suture is one that lacks a colouredlayer that is present on the rest of the suture body. A plasticbiocompatible material bearing a colourant may be applied on the othersections of the suture, and at least where the other sections border thesection of interest. Examples of such materials are discussed above. Asin the foregoing examples, demarcating the suture section of interestmay be effected in the suture manufacturing process either before orafter forming retainers.

Another example of a reverse-marked suture is one having a coaxialstructure wherein each coaxial layer having a different colour, and aportion of the outermost layer(s) is removed to visually expose a layerbelow. For example, a dual-layer monofilament polypropylene suture canbe produced with a white inner core (intercoaxial layer) with a blueouter coaxial layer, and portions of the outer layer can be removed tovisually expose the white inner monofilament to mark the suture sectionof interest.

Yet another example of a reverse-marked suture is one in which anexternal coating is removed (or partially removed) from the suture inthe suture section of interest, and where either the coating or basesuture has a contrasting colour difference. This technique of removing(or partially removing) material in the suture section of interest mayalso create a tactile demarcation of the suture section of interest.

The marking may include an echogenic compound, radio-detectablecompound, or magnetic resonance imaging detectable compound. For examplethe suture section of interest provided with barium sulfate (BaS04),such as by impregnating the suture with barium sulfate or adding acoating containing barium sulfate, will be detectable by electromagneticenergy. In the case of x-ray detection, the barium sulfate markedsection of interest would be radiopaque. Likewise, computed tomography(CT) scans or computed axial tomography (CAT) scans can be used todetect the radio detectable section of interest. The use ofelectromagnetic energy for radio detection of the transition section isnot limited to using x-ray wavelengths as other radio frequencies may beused. Likewise, gadolinium (Gd) or gadolinium compounds can be used forthe marking of the suture section of interest especially when thedetection will be done by using magnetic resonance imaging (MRI). Theuse of radio detectable or magnetic resonance imaging detectable markingmay be useful to later identify the transition segment for cutting inorder to remove the suture. FIG. 1B illustrates a magnified view ofself-retaining suture 100 in region 142. As shown in FIG. 1B, aplurality of retainers 130 is distributed on the surface of suturethread 120. The affixation of self-retaining sutures after deployment intissue entails the penetration of retainer tips 132 into the surroundingtissue resulting in tissue being caught between the retainer 130 and thebody of suture thread 120. The inner retainer surface 134 of theretainer 130 that is in contact with the tissue that is caught betweenthe retainer 130 and the body of suture thread 120, is referred toherein as the “tissue engagement surface” or “inner retainer surface.”As illustrated in FIG. 1B, each retainer 130 has a tip 132 and innerretainer surface 134. When self-retaining suture 100 is moved in thedirection of arrow 156, retainers 130 in region 142 lie flat against thebody of suture thread 120. However, when self-retaining suture 100 ismoved in the direction of arrow 158, tips 132 of retainers 130 in region142 engage tissue surrounding suture thread 120 and causes retainers 130to fan out from suture thread 120 and engage the tissue with innerretainer surface 134 thereby preventing movement of the suture in thatdirection. In region 146, there is a plurality of retainers 130 arrangedsuch that the suture can be moved through tissue in the direction ofarrow 158 but resists movement in the direction of arrow 156.

The distribution of retainers may also vary, in accordance with variousembodiments of the invention. FIGS. 2A, 2B, and 2C show a range ofretainer distributions and patterns that can be used in conjunction witha self-retaining suture. FIG. 2A shows a single helix distribution ofretainers on a self-retaining suture according to an embodiment of theinvention. FIG. 2B shows a double helix distribution of retainers on aself-retaining suture according to an embodiment of the invention. FIG.2C shows a high quadra-helix density distribution of retainers on aself-retaining suture according to an embodiment of the invention.

As shown in FIG. 2A, the suture thread is a 4-0 suture having a diameterof 250 μm. The self-retaining suture 200 includes a plurality ofretainers 204 arranged in a helical pattern around and along the suturethread 202. As shown in FIG. 2A, the helix makes 5.7 twists per inch. Inan embodiment the self-retaining suture has a barbed section 212 atleast 60 mm in length and a 100 mm unbarbed lead 210, 214 on either sideof the barbed section 212. The barbed section 212 may have retainers 204in one orientation or in different orientations. Each retainer is 500 μmfrom tip of depression to base of cut—measured axially—see arrow 216.The distance between the base of one retainer and the base of theadjacent retainer in the same helix (pitch) is 600 μm—measuredaxially—see arrow 218.

In the embodiment shown in FIG. 2A, retainers 204 are distributed at adensity of 42 retainers per inch or 0.50 retainers per suture diameterin axial length. The retainer density of retainers in retainers perinch=n*25400/pitch (where n=no. of retainers in pattern e.g. n=1 forsingle helix, n=2 for double helix, n=4 for quadra-helix and wherein25400 is the number of micrometers per inch). The retainer density ofretainers in retainers per suture diameter in axial length=n*(suturediameter)/pitch (where n=no. of retainers in pattern e.g. n=1 for singlehelix, n=2 for double helix, n=4 for quadra-helix and wherein 25400 isthe number of micrometers per inch). Note that it is not necessary thatretainers be provided over one inch of suture thread.

Referring now to FIG. 2B which shows a double helix distribution ofretainers 224 on a self-retaining suture 220. As shown in FIG. 2B, thesuture thread is a 4-0 suture having a diameter of 250 μm. Theself-retaining suture 220 includes a plurality of retainers 224 arrangedin a double helical pattern (n=2) around and along the suture thread222. As shown in FIG. 2B, each helix makes 4.2 twists per inch. Thehelixes are also shifted axially by 0.49 mm relative to one another. Inan embodiment, the self-retaining suture 220 has a barbed section 232 atleast 100 mm in length and a 100 mm unbarbed lead 230, 234 on eitherside of the barbed section 232. The barbed section 232 may haveretainers 224 in one orientation or in different orientations. Eachretainer is 310 μm from tip of depression to base of cut—measuredaxially—see arrow 236. The distance between the base of one retainer andthe base of the adjacent retainer in the same helix (pitch) is 410μm—measured axially—see arrow 238. In the embodiment shown in FIG. 2B,the retainers 224 are distributed at a density of 123 retainers per inchor 1.21 retainers per suture diameter in axial length. The ratio ofcombined retainer length to suture length can be calculated by theformula n*(retainer length)/pitch and in FIG. 2B the ratio is 2*310μm/410 μm or 1.51.

Referring now to FIG. 2C which shows a high density distribution ofretainers 244 on a self-retaining suture 240, the suture thread is a 4-0suture 250 μm nominal diameter. The self-retaining suture 240 includes aplurality of retainers 244 arranged in groups of four retainers in oneplane (n=4), each arranged at 90 degrees spacing—a quadra-helixdistribution. Each adjacent set of four retainers is offset to theadjacent sets by 45 degrees. In an embodiment, the self-retaining suturehas a barbed section 252 at least 60 mm in length and a 100 mm unbarbedlead 250, 254 on either side of the barbed section 252. The barbedsection 252 may have retainers 244 in one orientation or in differentorientations. Each retainer is 180 μm from tip of depression to base ofcut—measured axially—see arrow 256. The distance between the base of theretainer in one set and the base of the adjacent retainers (pitch) is280 μm—measured axially—see arrow 258. In the embodiment shown in FIG.2C, the retainers 244 are distributed at a density of 362 retainers perinch or 3.57 retainers per suture diameter in axial length.

Kits may be provided in accordance with embodiments of the presentinvention. Referring to FIG. 4, kit 400 includes a packaged suture 410(including a suture as disclosed herein), a needle driver 420, forceps430, scissors 440, and a tongue depressor 450.

FIGS. 5A and 5B illustrates a bi-curve needle that is particularlysuited for use with the devices and methods described herein. Thebi-curve needle 500 includes a first portion 502 adjacent to theproximal end 503 and a second portion 504 adjacent to the distal,tapered end 505 of the needle, and the needle preferably has an overalllength of 28-32 mm. The first portion has a smaller radius of curvaturethan the second portion, which is more clearly shown in the illustrationof FIG. 5B. Bi-curve needles are known in the art for use in variousprocedures including ophthalmic procedures.

Soft Palate Elevation Procedures

The methods of the present invention include the deployment of abidirectional self-retaining suture as disclosed above in a partiallytrapezoidal suture pathway into soft palate tissue to effect theelevation of the tissue. Referring now to FIG. 3A, the clinician firstlocates the junction of the soft and hard palate and inserts the firstend of the suture into the soft palate at an insertion point indicatedas “1” to one side of the palate midline and between the junction of thehard and soft palates and the posterior end of the soft palate. Theclinician then passes the first end laterally across the medial portionof the soft palate to a first exit point, indicated as “2”, to the otherside of the palate midline and between the junction of the hard and softpalates and the posterior end of the soft palate. The points “1” and “2”may be about half the distance posterior to the junction of the soft andhard palate. Next, the clinician may pull the suture until some of theretainers in the plurality of retainers adjacent to and oriented to thesecond end of the suture engage around the midpoint of the suture, or,where the midpoint or transition segment is marked, until the cliniciansees the marking approach the insertion point. The clinician thenre-inserts the first end into the first exit point “2” and deploys thefirst end through the soft palate posteriorly and away from the palatemidline to a second exit point, indicated as “3”, and urges the firstend out of the soft palate at the second exit point “3”, drawing thesuture out through the second exit point “3”. Finally, the clinicianthen takes the second end of the suture and inserts it into theinsertion point “1” and deploys the second end through the soft palateposteriorly and away from the palate midline to a third exit point “4”.The second end of the suture is then drawn out of the tissue at the exitpoint “4”.

The clinician may adjust and trim each end of the suture either uponexiting the suture from points “3” and “4”, respectively, or he or shemay do so at the end of the procedure. In a further alternative, theclinician may leave some portion of the suture exposed at each of thesepoints, for adjustment in 1-3 days in the clinic followed by cutting thesuture flush with the mucosa allowing the distal ends to bury themselvesbelow the mucosa. In addition, to further elevate the soft palate, theclinician may wish to draw the suture anteriorly and cranially whendrawing the suture out of exit points “3” and “4”.

Referring now to FIG. 3B, the volumetric increase in the airway passagecan be seen as the difference “C” between the position of the softpalate before the procedure (indicated as “A”) and the position of thesoft palate after the procedure (indicated as “B”).

Materials

Suture threads described herein may be produced by any suitable method,including without limitation, injection molding, stamping, cutting,extrusion, and so forth. In preferred embodiments, the suture threadsare drawn polymeric monofilaments having a high strength to diameterratio. Polymeric suture threads/filaments may be manufactured orpurchased for the suture body, and the retainers can be subsequently cutonto the suture body. The suture threads/filaments can be biodegradableor nondegradable as desired for a particular application. The retainerscan be mechanically-cut using blades, cutting wheels, grinding wheels,and so forth. During cutting, either the cutting device or the suturethread may be moved relative to the other, or both may be moved, tocontrol the size, shape and depth.

Additionally, self-retaining sutures described herein may be providedwith compositions to promote healing and prevent undesirable effectssuch as scar formation, infection, pain, and so forth. This can beaccomplished in a variety of manners, including for example: (a) bydirectly affixing to the suture a formulation (e.g., by either sprayingthe suture with a polymer/drug film, or by dipping the suture into apolymer/drug solution), (b) by coating the suture with a substance suchas a hydrogel which will in turn absorb the composition, (c) byinterweaving formulation-coated thread (or the polymer itself formedinto a thread) into the suture structure in the case ofmulti-filamentary sutures, (d) by inserting the suture into a sleeve ormesh which is comprised of, or coated with, a formulation, or (e)constructing the suture itself with a composition. Such compositions mayinclude without limitation anti-proliferative agents, anti-angiogenicagents, anti-infective agents, fibrosis-inducing agents, anti-scarringagents, lubricious agents, echogenic agents, anti-inflammatory agents,cell cycle inhibitors, analgesics, and anti-microtubule agents. Forexample, a composition can be applied to the suture before the retainersare formed, so that when the retainers engage, the engaging surface issubstantially free of the coating. In this way, tissue being suturedcontacts a coated surface of the suture as the suture is introduced, butwhen the retainer engages, a non-coated surface of the retainer contactsthe tissue. Alternatively, the suture may be coated after or duringformation of retainers on the suture if, for example, a fully-coatedrather than selectively-coated suture is desired. In yet anotheralternative, a suture may be selectively coated either during or afterformation of retainers by exposing only selected portions of the sutureto the coating. The particular purpose to which the suture is to be putor the composition may determine whether a fully-coated orselectively-coated suture is appropriate; for example, with lubriciouscoatings, it may be desirable to selectively coat the suture, leaving,for instance, the tissue-engaging surfaces of the sutures uncoated inorder to prevent the tissue engagement function of those surfaces frombeing impaired. On the other hand, coatings such as those comprisingsuch compounds as anti-infective agents may suitably be applied to theentire suture, while coatings such as those comprising fibrosing agentsmay suitably be applied to all or part of the suture (such as thetissue-engaging surfaces). The purpose of the suture may also determinethe sort of coating that is applied to the suture; for example,self-retaining sutures having anti-proliferative coatings may be used inclosing tumour excision sites, while self-retaining sutures withfibrosing coatings may be used in tissue repositioning procedures andthose having anti-scarring coatings may be used for wound closure on theskin. As well, the structure of the suture may influence the choice andextent of coating; for example, sutures having an expanded segment mayinclude a fibrosis-inducing composition on the expanded segment tofurther secure the segment in position in the tissue. Coatings may alsoinclude a plurality of compositions either together or on differentportions of the suture, where the multiple compositions can be selectedeither for different purposes (such as combinations of analgesics,anti-infective and anti-scarring agents) or for their synergisticeffects.

Although the present invention has been shown and described in detailwith regard to only a few exemplary embodiments of the invention, itshould be understood by those skilled in the art that it is not intendedto limit the invention to the specific embodiments disclosed. Variousmodifications, omissions, and additions may be made to the disclosedembodiments without materially departing from the novel teachings andadvantages of the invention, particularly in light of the foregoingteachings. Accordingly, it is intended to cover all such modifications,omissions, additions, and equivalents as may be included within thespirit and scope of the invention as defined by the following claims.

What is claimed is:
 1. A method of approximating soft palate tissueusing a bidirectional self-retaining suture having first and secondtissue-penetrating ends, first and second pluralities of tissueretainers oriented towards the first and second ends, respectively, andseparated by a retainer-free transition segment, the method comprising:a. inserting the first end of the suture into a soft palate at aninsertion point to one side of a palate midline and between a junctionof the hard and soft palates and a posterior end of the soft palate; b.deploying the first end through the soft palate across the palatemidline to a first exit point to the other side of the palate midlineand between the junction of the hard and soft palates and the posteriorend of the soft palate; c. urging the first end out of the soft palateat the first exit point and drawing the suture through the soft palateuntil the second plurality of tissue retainers engage the tissue; d.re-inserting the first end into the first exit point and deploying thefirst end through the soft palate posteriorly and away from the palatemidline to a second exit point; e. urging the first end out of the softpalate at the second exit point and drawing the suture out through thesecond exit point; f. inserting the second end into the insertion pointand deploying the second end through the soft palate posteriorly andaway from the palate midline to a third exit point; and g. urging thesecond end out of the soft palate at the third exit point and drawingthe suture out through the third exit point.
 2. The method according toclaim 1, further comprising trimming the suture flush with the secondand third exit points.
 3. The method according to claim 1, furthercomprising drawing the suture anteriorly and cranially in step “g” toincrease elevation of the soft palate.
 4. The method according to claim3, whereby the drawing of the suture results in a volumetric increase inan airway of a patient.
 5. The method according to claim 1, wherein thefirst and second tissue penetrating ends of the suture further comprisefirst and second bi-curved needles attached to first and second ends ofthe suture respectively.
 6. The method according to claim 5, wherein thebi-curved needle has a length of approximately 28-32 mm.